Safety control valve



April 13, 1937. G. W. @BELL SAFETY CONTROL VALVE Filed March 2l, 1952 MY NN eazye Wlfball q/Jhu SH01/MW or boiler itself includes a Patented Apr. 13, 1937 UNITED STATES SAFETY CONTROL VALVE George W. Isbell, Baltimore, Md. Application March 21, 1932, Serial No. 600,310

3 Claims.

This invention relates to a safety control valve and has for an object to provide an improved safety control valve especially useful in connection with a fluid fuel burning heater such as an oil burning boiler.

It is a further object of this invention to provide a safety control valve for an oil or gas burning heater or boiler and the like which will make it impossible to light up the heater or boiler unless water is actually flowing through the coils.

It is a further object of this invention to pro" vide a safety control valve for an oil or fuel burning heater` or boiler which will automatically cut off the oil or fluid fuel from the boiler instantly should the water fail to feed continuously into the boiler or steamer for any reason whatsoever. As is well known in boilers or Steamers using a constant supply of water to replace the steam given off, a damaging and dangerous explosion will occur should the water supply be cut off while the fuel supply continues to heat the boiler. To prevent this the safety control valve comprising this invention is so constituted that it will immediately cut off the fuel for the oil or gas from the burner when either the water supply fails or the water supply is blocked in the boiler, causing back pressure in the Water supply line.

With the foregoing and other objects in view, as will hereinafter become apparent, this invention comprises the constructions, combinations, and arrangements of parts, hereinafter set forth, disclosed and shown on the accompanying drawing. In this drawing,

Figure 1 is a side elevation of the safety control valve, and

Figure 2 is a sectional view taken on line 2-2 of Figure l showing the operation of said safety control valve.

The valve constituting this invention will work satisfactorily on steam from l lbs. to 400 lbs. pressure and is an entirely safe device for such purposes. The type of steamer or boiler that this valve is made to work on is commonly used in garages, paint shops and the like. 'Ihe steamer series of coils and is fed by a hydraulic pump forcing water through these coils at approximately 125 lbs. This Water is heated by an oil burner, the water entering the bottom and passing out of the top turned into steam. Should anything happen to this water pump or to the electricity or motor operating the pump, the water would cease flowing into the coils and the fire would continue burning with no Water going into the coils. This would very shortly burn through the coils causing explosion and ruining the boiler or steamer as well as causing a possibility of serious damage to the shop and to the workers in the shop.

With the safety device of this invention all such dangers such as re hazards and destruction of boiler tubes would be eliminated.

The safety control valve is shown in general at I0. Passing through this valve is a water pipe II feeding the water from the pump (not shown), in the direction of the arrow through the pipe Il, into the Valve It, through the pipe I2, the back pressure check valve I3, and the union Ill, which is threaded at I 5 for connection to the coil of a boiler (not shown).

The oil or fuel supply passes through a pipe it through a cut off valve Il and a pipe I8, leading to the burner (not shown). The pipe II feeds the water or fluid into a chamber I9 which is closed olf by a diaphragm 20, this diaphragm 2E being made preferably copper secured between the valve body 2l and the valve body cap 22. Resting on top of the phragm is a seat 23 in the chamber 2li formed between the diaphragm 20 and the Valve body 2 i, the seat 23 having secured thereto the stem 25. The stem passes into the chamber 2li through a leak proof packing 2S, which however will allow the stem' 25 to move upwardly and downwardly therethrough.

Surrounding the stem 25 within the chamber 24 is a spring 2l tending to press the seat123 and hence valve stem 25 downwardly, this spring being of such a strength that it takes at least 6 lbs. of pressure to compress it/to the position shown in Figure 2. Adjustably secured to the 5 stem 25 by means of the lock nuts 28 and 29 is a rectangular shaped yoke 30, the top of this yoke 3U being spaced slightly above the top 32 of a needle valve 33, the top 32 of needle valve 33 having a cross bar 3| serving as a handle.

'I'his needle valve 33 passes into the valve body 2l through a leak proof packing 35 Which may be adjusted by the nut 34. A back pressure pipe 36 secured to the union I4 at 31 enters the chamber 2li at 38.

In operation, this safety control valve will work satisfactorily on steam from 10 lbs. to 400 lbs. pressure and is an entirely safe device for such purposes. The water is supplied from a hydraulic pump (not shown) at approximately 125 lbs. of pressure, passing through pipe II, the chamber I9, the pipe I2 and the back pressure check valve I3 and union I4, through the threaded end I5 to the coils in the furnace.

As will be observed, the back pressure check of two sheets of flexible V- valve I3 is a poppet valve allowing the pressure to open the Valve in the direction that the water should normally flow as shown by the arrow, but not allowing any pressure to pass in the opposite 5 direction. This valve will be said to operate preferably at lbs. pressure, thereby insuring that there will be at leastI 6 lbs. pressure to compress the spring 21. When the spring 21 is so compressed it will raise the yoke 3U to the posi- 1G tion shown, allowing the needle valve 33 to be manually raised by means of the handle bar 3l, thus opening the valve I1 and allowing the oil to flow through from pipe I5 to pipe I8 to the burners in the furnace. As will be observed, the l5 pipes I6 and I8 are secured on ngers 39 and 4D projecting upwardly from the valve body 2|.

Should for any reason the water supply through pipe II fail coming, as for instance if the pump should break down or the motor for the pump cease to operate, the pressure in chamber I9 will drop away to approximately nothing, Spring 21 will then expand against the flexible diaphragm 20 drawing stem 25 down with it, which in turn will draw yoke 30 downwardly and the top of the yoke 30 will press against the top 32 of needle valve 33 downwardly until the needle valve 33 will immediately and completely close off the valve I1 and instantly stop the supply of oil or gas flowing into pipe I8 and automatically cause the re in the boiler to be extinguished through lack of fuel, thereby preventing any possibility of explosion in the boiler or steamer.

If the steam generated in the boiler should fail to continue through the coils in the proper 35 manner and instead should work back-through the water supply pipe 55, the poppet valve in valve I3 will immediately close, causing the back pressure to exert itself through the back pressure pipe 36 and opening 38 into chamber 24. 40 The pressure in chamber 24 will then become greater than the pressure in chamber I9 and the diaphragm 20 will yield to allow spring 21 to move seat 23 downwardly, thus moving the stem 25 downwardly and yoke 30 to close the needle valve 33 in the same manner as above described. As will be seen, this safety valve operates to cut off the fuel supply which may be oil or any other liquid or gaseous fuel immediately whenever the water supply should fail or when there is greater back pressure through the water supply line than the pressure in the water supply line can overcome. Whenever this condition arises the spring 21 operates immediately through the seat 23 and stem 25 to draw down the yoke 30 and close the needle valve 33 in the oil supply valve I1.

The novel features and the operation of this device will be apparent from the foregoing description. While the device has been shown and the structure described in detail, it is obvious that this is not to be considered limited to the exact form disclosed and that changes may be made therein within the scope of what is claimed withoutv departing from the spirit of the invention.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

l. A safety control valve comprising a fluid supply line and a fuel supply line, a cut off valve in said fuel supply line, a pressure chamber in said fluid supply line, a back pressure chamber, a flexible diaphragm separating said chambers, means connecting said back pressure chamber to the fluid supply line, and means operable by said diaphragm upon increase in pressure in said back chamber over the pressure in said pressure charnber to operate said out off valve, said means being normally spaced from said cut off valve.

2. A safety control valve comprising a fluid supply line, a fuel supply line, a cut oi Valve in said fuel supply line, a pressure responsive means in said fluid supply line, a yoke connected to said pressure responsive means, said yoke being normally positioned adjacent to but spaced from said cut 'off valve, said pressure responsive means being operative to move said yoke into contact with said cut off valve to move the latter to closing position.

3. A safety control valve comprising a uid supply line, a fuel supply line, a out off valve in said fuel supply line, a pressure chamber and a back pressure chamber connected to said fluid supply line, a flexible diaphragm separating said pressure from said back pressiue chamber, a valve in said fluid line keeping the pressure in the pressure chamber normally in excess of the pressure in the back pressure chamber, means in said back pressure chamber tending to close said fuel cut olf valve, Ysaid means being normally spaced from said valve, said valve closing means being maintained in normally spaced condition when the pressure in the pressure chamber exceeds the pressure in the back pressure charnber.

GEORGE W. ISBELL. 

